Chapter 12 – Neurology I

Vocabulary flashcards covering main terms and definitions from Chapter 12 – Neurology I lecture notes.

Central Nervous System (CNS)

Portion of the nervous system consisting of the brain and spinal cord.

Peripheral Nervous System (PNS)

All nervous tissue outside the CNS; includes nerves and ganglia.

Afferent Division

Pathway that carries sensory information from receptors to the CNS.

Efferent Division

Pathway that carries motor commands from the CNS to effectors.

Somatic Receptors

Sensory receptors located in skin, skeletal muscles, and joints.

Visceral Receptors

Sensory receptors located in internal organs (viscera).

Special Receptors

Receptors for special senses such as vision, hearing, smell, and taste.

Effectors

Target organs (muscles or glands) that respond to motor nerve signals.

Somatic Nervous System

Motor subdivision that controls voluntary skeletal muscle contraction.

Autonomic Nervous System

Motor subdivision that controls involuntary activity of smooth muscle, cardiac muscle, and glands.

Neuron

Excitable cell that conducts electrochemical impulses and releases neurotransmitters.

Neuroglia (Glial Cells)

Supporting cells of nervous tissue that can divide by mitosis and assist neurons.

Cell Body (Soma)

Portion of a neuron containing the nucleus and most organelles.

Nuclei (Neural)

Clusters of neuronal cell bodies located within the CNS.

Ganglia

Clusters of neuronal cell bodies located in the PNS.

Dendrite

Neuron process that receives incoming signals from other cells.

Axon

Long neuron process that propagates action potentials away from the cell body.

Synapse

Functional junction where a neuron communicates with another cell.

Presynaptic Neuron

Neuron that releases neurotransmitter at a synapse.

Postsynaptic Cell

Cell (neuron, muscle, or gland) that receives neurotransmitter at a synapse.

Synaptic Knob (Terminal)

Bulb-shaped ending of an axon containing neurotransmitter-filled vesicles.

Synaptic Cleft

Narrow extracellular gap between the presynaptic and postsynaptic membranes.

Oligodendrocyte

CNS glial cell that forms the myelin sheath around multiple axons.

Microglia

Small, phagocytic CNS glial cells that migrate toward injury via chemotaxis.

Astrocyte

Star-shaped CNS glial cell that regulates the extracellular environment and forms perivascular feet on capillaries.

Ependymal Cell

Ciliated epithelial cell lining CNS cavities; helps produce and circulate cerebrospinal fluid.

Schwann Cell

PNS glial cell that forms the myelin sheath around a single axon.

Satellite Cell

PNS glial cell that provides metabolic and structural support to neuron cell bodies in ganglia.

Myelin Sheath

Lipid-rich wrapping around axons that speeds impulse conduction.

Bipolar Neuron

Neuron with one dendrite and one axon; found in special sense organs.

Unipolar Neuron

Neuron with a single process that splits into peripheral and central branches; typical sensory neuron.

Multipolar Neuron

Neuron with one axon and multiple dendrites; most common type, including motor neurons and interneurons.

Sensory Neuron

Afferent, usually unipolar neuron that conveys information from receptors to the CNS.

Interneuron

Multipolar neuron within the CNS that processes and relays information between neurons.

Motor Neuron

Efferent, multipolar neuron that carries impulses from the CNS to effectors.

Axon Regeneration (PNS)

Process aided by Schwann cells in which severed peripheral axons regrow to re-establish connections.

Glial Scar

Barrier of astrocyte processes that forms after CNS injury and inhibits axon regrowth.

Apoptotic Receptors

Membrane proteins induced on injured CNS axons that trigger programmed cell death.

Inhibitory Proteins (CNS)

Molecules in myelin and glial scar that prevent axonal sprouting and regeneration.